Dry dock staging



DRY DGCK STAGING Ciidord W. Valentine, Newport News, and Kenley N. .Burchiield, Norfolk, Va.

Application July 15, 1953, Serial No. 368,238

6 (Ilairns. (Cl. 304-14) (Granted under Title 35, U. S. Code (1952), sec. 266) V This invention may be manufactured and used by or for the'Government of the United States for governmental purposes without the payment of anyroyalties thereon or therefor.

This invention relates to staging and more particularly to staging for use in a dry clock.

In the dry docking of ships it is a conventional practice to build staging around the ship to enable the dock crew to work on the hull. In most instances the staging consists of an arrangement of metal or wooden uprights and braces suitably fabricated in tiers adapted to support the stage planking. Although the use of prefabricated staging. components has expedited such assemblies, the installation time still is quite lengthy, and when ships are brought in for relatively short periods of time, such as for painting, the erection of the staging becomes disproportionately expensive. Permanent prefabricated staging mounted on tracks at the base of the launching ways has been suggested, but, as can readily be appreciated, such apparatus is cumbersome and presents difficult stowage problems.

Another objectionable characteristic of most presently used staging is that it is adapted to rest or be supported on the floor of the dry dock, so that Very little work can be commenced on the ship until the dock has been pumped dry and the staging erected on it. This is particularly disadvantageous in painting procedures, because such 2,830,853 Patented Apr. 15, 1958 2 mounted around the axis of the upright. The staging is particularly suitable for permanent attachment to a floatiug dry dock, where stowage always is a critical problem.

The uprights, preferably, are spaced along the dry dock wing walls to support stage planks around the docked ship, while the brackets are swingable to a stowed position adjacent these wing walls where they will not reduce the capacity of the dock or interfere with the docking of a ship. After the ship has been docked, the brackets with their stage planks attached may be swung toward the ships side and work commenced durin the pumping. The stage planks may be of a length to span the spacing between adjacent brackets with the ends of the planks overlapping and mounted to the brackets, most suitably, by a swivel connection, such as permits the staging to collapse in the manner of a lazy tong when the brackets are pivoted around the uprights. This arrangement has many advantages, such for instance, as simplifying the assembly and disassembly of the planking, permitting the planking to be retained on the brackets when a fully stowed position of the brackets is not required, and permitting the planks to be supported adjacent the ships side by an oblique arrangement of the brackets when sufiicient clearance is not available between the ships side and the deck for the fully extended position of the brackets.

. Each bracket may be horizontally extensible to position work initially entails the removal of wet sea growths,

and such growths are removed most easily while still wet. If the removal of these growths is delayed until the dock is pumped dry, a good portion of them will dry, harden and be removable only with relatively great dificulty.

Accordingly, it is an object of the present invention to provide staging which can be very expeditiously stowed in a position ready for use and which, when its use is desired, can be moved into operative, plank-supporting position in a minimum of time. t

A further object is to provide dry dock staging adapted to be supported by the vertical walls of the dry dock in such a manner that it can be moved into operative position while the dock is being pumped dry.

Another object is to provide a staging which can be permanently installed on a dry dock in such a position that it will not interfere with the docking of a ship, and also will not materiallyreduce the capacity of a dock to accommodate the ships for which it was designed.

Other more specific objects are to provide permanently attached staging that is both vertically and horizontally adjustable to support the stage planks in a ship contourconforming position; and to provide a staging that is formed of sections which are individually adjustable, easy to operate and nevertheless safe and compact.

Other objects will become apparent from the detailed description and accompanying drawings. I

According to the invention staging is provided which comprises a plurality of uprights adapted to be fixed to a supporting structure in spaced relation, each upright havinga vertically" adjustable bracket which is pivotally theplanks in a path to conform to the ships outline or contours. The brackets are vertically adjustable independently of the others by a suspension system controlled by a suitable manual or power-driven winch, preferably positioned above each upright to enable each bracket to be controlled from the main deck of the dry dock which is always above the water level. A safety mechanism may be provided on the bracket to automatically lock the bracket to the upright when the suspension system fails.

The preferred embodiment of the invention is illustrated in the drawings in which Fig. l is a plan view of a floating dry dock with the operative position of the staging shown in solid lines and the stowed position in broken lines; Fig. 2 a partial front elevational view taken along line 22 of Fig. 1 showing the sta ing in stowed position along one of the wing walls of the dry dock; Fig. 3-a partial top view of the staging positioned against the wing wall with the stage planks attached; Fig. 4 an enlarged side elevational view taken along line l-4 of Fig. 1; Fig. 5 a section of the upper bracket sleeve taken along line 5-5 of Fig. 4; Fig. 6 a section of the bracket base taken along line 66 of Fig. 4; Fig. 7 a top view taken along lines 7-7 of Fig. 4 and Fig. 3 of a crosssection taken along line 83 of Fig. 4. p

In the drawings, ltl designates a floating dry dock of known construction comprising spaced wing walls 12 and 14 forming a well 16 to receive a ship is to be docked. To provide a suitable elevated support for the repair gang to work on the ships side, it has been the long practice procedure ,to fabricate the staging after the dock has been dewatered in the manner previously described. As can well be appreciated, the time required to install and disassemble the staging around a ship materially lengthens the stay in the dry dock as well as requires excessive handling. These disadvantages are applicable to all types of dry docks, and particuarly to floating dry docks where a large amount of loose staging gear imposes stowage and handling problems.

. Asshown in Figs. 1 and 2, the staging of this invention is formed of a plurality of uprights 2t) permanently see cured to the dry dock, preferably close to its-wing walls, so as to offer a minimum obstruction. Each upright, as may be seen, has suspended from it a bracket 22 adapted to supportstageplanks 24 which, of course, extend be tween adjacent brackets to form the working platform.

Uprights are positioned along the wingwalls in a spaced relationship such as will accommodate brackets 22 when swung from their extended position to their fully stowed broken line positions, the brackets in the latter position being laterally disposed against the wing walls and adapted to rest on saddles 25 and to be protected by fenders 26 also secured to the wingwalls as illustrated in Fig. 2.

As to the details of construction shown in Figs. 4-8, each upright 20, preferably, is made of a cylindrical pipe rigidly supported in close proximity to the wing wall by a base lug 28 located near the bottom of the well, and by an upper lug 30 located beneath deck 32. Bracket 22 may be triangularly formed of a vertical member 34, a brace 36, and a base 38, and as may be noted in Fig. 4, the bracket is provided with integral upper and lower cylindrical sleeves 42 and 44, each slidably positioned around upright 20 to enable the bracket to be vertically adjusted, as well as to permit it to pivot in a horizontal plane.

Bracket 22 is raised and lowered on the upright by a hoisting mechanism that includes a winch 48 supported on a foundation plate 50 secured to the top of upright 20, the winch being operated by a socket wrench 52 extending through an opening in deck 32 and adapted to be connected to the worm and worm wheel 53. One end of wire rope 54 is anchored to a foundation plate web 55 by a shackle 56 and is wrapped around a winch drum 57 through a swivel block 58 attached to a safety brake 60 mounted on upper sleeve 42.

Safety brake 60, shown in Figs. 4 and 5, comprises a generally S-shaped brake arm 62 pivoted at 64 to checks 66 welded to sleeve 42, brake arm 62 being intermediately connected to swivel block 58 by a shackle 68. Upper sleeve 42 is provided with a vertical slot 70 through which the lower end of brake arm 62 projects so as to grip upright 20 by means of its serration 72 when any accidental parting of rope 54 relieves the tension on arm 62 and permits it to pivot. The arm will pivot clockwise due to weight 74 mounted on its upper end and further due to a biasing spring 75 anchored to brace 36.

To permit the bracket to be adjusted or disposed in appropriate positions for supporting stage planks 24 adjacent the varying ship contours of base 38 of the bracket is made hollow to telescopically receive a base extension 76 preferably rectangular in cross-section, as shown in Fig. 6 to prevent twisting. The housed inner end of extension 76 is provided with a pair of rollers 78 and 80 mounted on shafts 82 and 84 to the vertical walls 86 and 88 of extension 76 and arranged to roll on the upper and lower walls 90 and 92, respectively, of base member 38. The intermediate portion of extension 76 is supported on roller 94 mounted, by a shaft 96, on checks 98 that forms the junction of brace 36 and base member 38, roller 94 extending through a window 99 in the latter to engage extension 76. Members 38 and 76 are fixed in any adjusted length by a locking pin 100 (Fig. 8) adapted to be extended through holes 102 in extension 76 and one set of a plurality of longitudinally spaced holes 104 in base member 38.

Stage planks 24 are supported by the free end of extension 76 and, preferably, on an arm 106 that is pivotally mounted on a pin 108 carried in the extension to enable the bracket to be movable in a horizontal direction relative of the planks when the staging is swung toward the docks. The overlapping plank ends are supported on arm 106 between a life line stanchion 109 and an eyebar 110. An intermediate staple 112 secured on arm 106 is adapted to extend through the elongated opening 113 in stage planks 24, which exist in the laminated type of planking illustrated, with the planks clamped by a staple wing nut 114 in overlapping relation on each bracket. Also, as may be noted, staple 112 is made of sutficient' length to permit the overlapping plank ends to be retained in oblique or non-parallel position to each other when an '4 adjacent bracket is moved to a different level. An aperture 116 in the free end of arm 106 provides for the attachment of a line 118 by which the brackets may be swung by the crew toward and away from the ships side.

The operation of the staging is readily apparent from the above description. When the staging is in a stowed position, as in Fig. 2 planks 24 have been removed and brackets 22 are supported in saddles 25 against the wing walls and protected by fenders 26. To place the staging in condition for use, the brackets are lifted by winches free of saddles 25 and swung sufficiently free of the wing wall to permit the attachment of planks 24, this arrangement of the staging being such that the base members 38 are almost parallel to planks 24, with extensions 76 fully collapsed and extension arm 106 positioned substantially at right angles with extensions. This position of the staging may be considered as a temporary stowage, such as might be employed when the dry dock is used with such frequency as could render the complete securing of the staging impractical, or when the ships being docked are of a size that makes it unlikely that the staging will be damaged. As soon as the docked ship is supported on the keel blocks, brackets 22, having been elevated to the desired level, may be swung on their respective uprights 20 against the ships side by lines 118, extensions 76 being withdrawn from base members 38, where necessary, and extension arms 106 being pivoted on their extension 76 and locked in the desired adjustment by locking pins 100. Thus, the staging may be set in position and work commenced on the docked ship while the dock is being pumped, with a consequent saving of docking time and the advantage of being able to clean the ships sides while wet. As work progresses, brackets 22 are lowered by the respective winches, and, where necessary, extension arms 106 may be lengthened and locked in the new position. It may be noted that brackets 22 may be lowered independently of each other by their respective winches and positioned at different levels in a nonparallel relation. To permit this, however, wing nuts 114 should be loosened to allow the stage planks to slide relatively to one another and thus compensate for the increased distance between adjacent brackets and permit the overlapping plank ends to align themselves obliquely. Where it is found that there is insufl'icient clearance between a docked ship and the wing wall to permit brackets 22 to extend in a position normal to the wing wall, the brackets may be swung to an acute angle and the extension arms pivoted to support planks 25 adjacent the ships side.

As the brackets are operable independently of each other, any number or arrangement of brackets may be used, such as in instances where only a portion of the ships side is to be worked. When the staging is no longer needed, each bracket 22 may be easily and quickly elevated to permit the dry dock to be filled without delay.

I The staging may then be swung to the temporary stowed position in which the planks are swung toward the wing walls to abut braces 36 and be in a position for the next docking. Or, if desired, the planks may be removed and the staging secured as in Fig. 2.

According to the invention, staging is provided that may be permanently secured to a supporting structure, such as a dry dock, and, in that position, moved from a platform forming to a stowed position with a minimum of effort and time and without substantially decreasing the capacity of the dry dock. The staging is composed of a plurality of independently movable and operated brackets between which stage planks are supported whereby any or all sections of the docked ships may be worked simultaneously. The staging is vertically and horizontally adjustable to accommodate docked ships of various heights and widths and permits the ships to be worked during the I dewatering of the dry dock so as to materially reduce the labor necessary to clean the hull and, consequently, the stay time in the dock.

Qbviously many modifications and variations of the present invention are possible in the light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

We claim:

1. Stage-plank supporting apparatus for use in a drydock comprising a plurality of spaced uprights, a horizontally-extending bracket carried by and swingablymovable horizontally about the vertical axis of each up right, and a stage-plank supporting arm carried by and swingable about each bracket in the same horizontal plane as said bracket movement, whereby said supporting arms can maintain fixed positions during the horizontal swinging movements of said brackets, said uprights being spaced apart a distance greater than the length of said brackets for permitting said brackets to be swung substantially into the vertical plane of the uprights.

2. Stage-plank supporting apparatus for use in drydocks comprising a plurality of spaced uprights, a horizontal bracket pivotally mounted for horizontal swinging movement on each upright, a horizontal bracket-extension member adjustably carried by each bracket, and a stage-plank supporting arm swingabiy mounted on the free end of each bracket-extension member for horizontal swinging movement there about in the plane of said horizontal bracket-extension member, whereby said arms can maintain fixed positions during the swinging movements through said over-lapped ends whereby when said means i are released said planks are movable relative one to anof said brackets and their extension members, said uprights being spaced apart a distance greater than the length of said brackets and extension members for permitting said brackets to be swung substantially into the vertical plane of said uprights.

3. Apparatus in accordance with claim 2, said apparatus further having said brackets mounted for vertical adjusting on said uprights.

4. Stage supporting apparatus for use in a drydock comprising a plurality of spaced uprights, a horizontallyextending bracket carried by and swingably movable horizontally about the vertical axis of each upright, a stage, a stage-supporting arrn mounted on the free end of each bracket for swingable movement thereabout in the same horizontal plane as said bracket movement, said stage being formed of a plurality of longitudinally-disposed elongate planks having their adjacent end portions overlapped and directly supported by one of said supporting arms, and releasable plank-connecting means extending through and securing each of said over-lapped ends to a supporting arm, said connecting means extending loosely other both in longitudinal and horizontally rotative directions, said uprights being spaced apart a distance greater than the length of said brackets for permitting said brackets to be swung substantially into the vertical plane of the uprights.

5. Stage plank supporting apparatus for use in a drydock comprising a plurality of spaced uprights, a horizontally-extending bracket pivotally mounted for swinging movement about the vertical axis of each upright, a horizontal bracket-extension member adjustably carrie by each bracket, a stage, a stage supporting arm swingably mounted on the free end of each bracket-extension member for horizontal swingable movement thereabout, said stage being formed of a plurality of longitudinallydisposed elongate planks having their adjacent end portions over-lapped and directly supported by one of said supporting arms, and releasable plank-connecting means extending through and securing said over-lapped ends to a supporting arm, said connecting means ext nding loosely through said over-lapped ends whereby when said means are released said planks are movable relative one to another both in longitudinal and horizontally-rotative directions, said uprights being spaced apart a distance greater than the length of said brackets and extension members for permitting said brackets to be swung substantially into the vertical plane of said uprights.

6. Apparatus in accordance with claim 5, said apparatus further having said brackets mounted for vertical adjustment on said uprights.

References Cited in the file of this patent UNITED STATES PATENTS 127,967 Elliott June 18, 1872 727,407 Murphy May 5, 1903 895,833 Aungst Aug. 11, 1903 960,151 Blumenthal May 31, 1910 1,235,089 Wiking July 31, 1917 1,617,990 Donnelly Feb. 15, 1927 2,069,607 GaW Feb. 2, 1937 2,309,210 Phillips Jan. 26, 1943 2,419,145 Kersenbrock Apr. 15, 1947 2,425,302 Calhoun Aug. 12, 1947 2,582,528 Cranford Jan. 15, 1952 FOREIGN PATENTS 258,565 Germany Apr. 11, 1913 

